The purpose of this contract is to facilitate access to the best data on the distribution and correlates of pathophysiology, impairment, functional, and societal limitation and disability within the U.S. population. During this phase I feasibility study, the contractor shall begin to develop a Research Archive on Disability In the U.S. (RADIUS). The archive which will be achieved under a follow - on phase II contract if approved will be comprised of three kinds of machine-readable materials: (I) exemplary data sets; (2) measurement instruments; and (3) software to retrieve those portions of the data sets and measurement instruments relevant to a problem at hand. The archive when completed should be easy to use, yet extremely powerful. Its objective will be to serve the widest possible user constituency by offering all its products in a variety of machine-readable media (mainframe tapes, workstation tape cartridges, microcomputer floppy diskettes, CD-ROM) for a variety of mainframes, workstations, and microcomputers.